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Effect of intrinsic viscosity on solid-state microcellular foaming of polyethylene terephthalate

Published online by Cambridge University Press:  09 July 2013

Huimin Guo ,
Krishna Nadella  and
Vipin Kumar
Huimin Guo
Affiliation:
Department of Mechanical Engineering, University of Washington, Seattle, Washington 98195
Krishna Nadella
Affiliation:
MicroGREEN Polymers, Inc., Arlington, Washington 98223
Vipin Kumar*
Affiliation:
Department of Mechanical Engineering, University of Washington, Seattle, Washington 98195
*
a)Address all correspondence to this author. e-mail: [email protected]
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Abstract

Microcellular foams, with cells of the order 10 μm, have been studied for over two decades. But little research has been done to study the effect of molecular weight on solid-state microcellular foaming. In this study, polyethylene terephthalate (PET) with a range of intrinsic viscosity (IV) 0.68–0.81 dL/g was used to investigate the effect of molecular weight on microcellular foaming process and resulting foam microstructures and properties. In the saturation step, IV showed negligible effect on sorption and desorption of CO2 in PET for all the conditions explored. In the foaming step, we found relative density increased with increasing IV. Also, as IV increased, cell size decreased and cell nucleation density increased. We hypothesize that lower chain mobility in higher IV samples led to more localized cell nucleation, resulting in a higher nucleation density, and also more constraints for cell growth, resulting in a smaller cell size. In addition, higher IV foams were found to have smaller skin thicknesses.

Type
Invited Papers
Information
Journal of Materials Research , Volume 28 , Issue 17: Focus Issue: Advances in the Synthesis, Characterization, and Properties of Bulk Porous Materials , 14 September 2013 , pp. 2374 - 2379
Copyright
Copyright © Materials Research Society 2013 

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References

REFERENCES

Martini, J., Suh, N.P., and Waldman, F.A.: Microcellular closed cell foams and their method of manufacture. U.S. Patent No. 4 473 665, 1984.Google Scholar
Martini, J., Waldman, F.A., and Suh, N.P.: The production and analysis of microcellular thermoplastic foam. ANTEC Conf. Proc. 28, San Francisco, CA, 1982, p. 674.Google Scholar
Kumar, V. and Weller, J.E.: A process to produce microcellular PVC. Int. Polym. Proc. VIII, 73 (1993).CrossRefGoogle Scholar
Kumar, V. and Weller, J.E.: Production of microcellular polycarbonate using carbon dioxide for bubble nucleation. J. Eng. Ind. 116, 413 (1994).CrossRefGoogle Scholar
Nawaby, V. and Handa, P.: Fundamental understanding of the ABS-CO2 interactions, its retrograde behavior and development of nanocellular structures. ANTEC Conf. Proc. 2, Chicago, IL, 2004, p. 2532.Google Scholar
Wang, X., Kumar, V., and Li, W.: Low density sub-critical CO2-blown PLA foams. Cell. Polym. 26, 11 (2007).CrossRefGoogle Scholar
Goel, S.K. and Beckman, E.J.: Generation of microcellular polymers using supercritical CO2. Cell. Polym. 12, 251 (1993).CrossRefGoogle Scholar
Wool, R.P.: Polymer Interfaces: Structure and Strength (Hanser Publisher, Munich, 1995).Google Scholar
Nielsen, L.E. and Landel, R.F.: Mechanical Properties of Polymers (Reinhold, New York, 1994).Google Scholar
Lee, C.H., Lee, K-J., Jeong, H.G., and Kim, S.W.: Growth of gas bubbles in the foam extrusion process. Adv. Polym. Tech. 19, 97 (1999).3.0.CO;2-B>CrossRefGoogle Scholar
Stafford, C.M., Russell, T.P., and McCarthy, T.J.: Expansion of polystyrene using supercritical carbon dioxide: Effects of molecular weight, polydispersity, and low molecular weight components. Macromolecules 32, 7610 (1999).CrossRefGoogle Scholar
Fakirov, S.: Handbook of Thermoplastic Polyesters, Homopolymers, Copolymers, Blends and Composites, Illustrated Edition (Wiley-VCH Verlag GmbH, Weinheim, 2002), ch. 7.CrossRefGoogle Scholar
Kumar, V. and Weller, J.: A model for the unfoamed skin on microcellular foams. Polym. Eng. Sci. 34, 169 (1994).CrossRefGoogle Scholar
Stolarczuk, P.: Process to structure characterization of microcellular poly(ethylene terephthalate). Master’s Thesis, University of Washington, WA, 1995.Google Scholar
Colton, J.S. and Suh, N.P.: The nucleation of microcellular thermoplastic foam with additives: Part I: Theoretical considerations. Polym. Eng. Sci. 27, 485 (1987).CrossRefGoogle Scholar
Legrand, D.G. and Gaines, G.L.J.: The molecular weight dependence of polymer surface tension. J. Colloid Interface Sci. 31, 162 (1969).CrossRefGoogle Scholar
Dee, G.T. and Sauer, B.B.: The molecular weight and temperature dependence of polymer surface tension: Comparison of experiment with interface gradient theory. J. Colloid Interface Sci. 152, 85 (1992).CrossRefGoogle Scholar
Chee, K.K.: Molecular weight dependence of surface tension of polystyrene as studied by the corresponding states principle. J. Appl. Polym. Sci. 70, 697 (1998).3.0.CO;2-L>CrossRefGoogle Scholar
Klempner, D. and Sendijarevic, V.: Polymeric Foams and Foam Technology (Hanser Publisher, Munich, 2004).Google Scholar